PDF permits the use of encryption as a means of restricting access or (re-)use of content. This may range from documents that can only be opened after providing a password, to disabling specific functionality (e.g. printing, copying content).
- Content may become inaccessible if passwords are not known (even though "cracking" is often technically possible, institutions may not be legally permitted to do this)
- Printing / copy restrictions may complicated any future preservation actions
The Preflight component of [Apache+PDFBox] (an open source PDF/A validator) is able to detect encryption in a PDF (any PDF, doesn't have to be PDF/A!).
In Preflight 1.8.0 an open password results in error code 1.0 (syntax error) with the following accompanying description:
Syntax error, Error (CryptographyException) while creating security handler for decryption: Error: The supplied password does not match either the owner or user password in the document
In Preflight 2.0.0 only a 'syntax' error message is reported without any indication of anything encryption-related. Reported this as a bug
|Error code||Affected if expression returns True|
|Tool||Affected if expression returns True|
|[Apache+PDFBox]||"/preflight/errors/error/code = '1.0' and /preflight/errors/error/details = 'Syntax error, Error (CryptographyException) while creating security handler for decryption: Error: The supplied password does not match either the owner or user password in the document'"|
Recommendations on what action(s) to pursue in case file is affected by this problem. Optional.
Links to example files, preferrably from OPF Format Corpus, e.g. like this:
- http://www.opf-labs.org/format-corpus/jp2k-test/resolution/balloon_aware.jp2 - Sample file Aware 3.19 (Capture Resolution)
References to literature, etc.